1. Field of the Invention
The invention relates to a longitudinal guide for a motor vehicle seat with a pair of carriers consisting of a seat carrier and a sliding bottom carrier, which are movable towards each other in their longitudinal direction and which are in contact with each other by means of sliding devices and/or rollers, whereby each carrier a) possesses at least two guide areas and each guide area of one carrier is adapted in a form to the related guide area of the other carrier in such a way that sliding devices and/or rollers are each taken up between two guide areas of different carriers and b) possesses at least one area of gearing, which is modelled is such away that it does not come into contact with at least one area of gearing of the corresponding other carrier under normal circumstances, but comes into contact, if the two carriers are separated from each other, and obstructs such a separation by means of gearing.
2. Description of the Art
Such longitudinal guides are known according to the state of the art. Usually a motor vehicle seat is connected with the understructure of the body of the motor vehicle seat by means of two such longitudinal guides. The carriers of a longitudinal guide are only in contact with each other in the guide areas, namely via the sliding devices and/or rollers, otherwise they are not in contact under normal circumstances. Usually two such guide areas are designed for each carrier, so that this results in two pairs altogether, which in the following will be called pairs of guide areas in effect with each other. Under normal circumstances at least the one area of gearing on each carrier is engaged free of contact into the corresponding other area of gearing of the other carrier, only when there is a sufficient separation of the carriers the gearing actually engages, the areas of gearing get in touch with each other and obstruct a further separation of the carriers of the longitudinal guide from each other.
According to the state of the art the carriers of a longitudinal guide are made of one piece on one hand and on the other hand both are manufactured from the same material. However, it is known from aluminium carriers to insert a narrow stripe made of steel or another hard material into at least one guide area, to avoid a direct contact from aluminium to aluminium or to bring about special characteristics such as a resilience for example. The sectional areas of the carriers, which are statically determining, are by all means made of aluminium or another light metal respectively.
Different demands are put on the two longitudinal guides of a motor vehicle seat. Depending on the arrangement of the safety belt one of the guides is stressed more strongly than the other. Furthermore it is known, that within a longitudinal guide, a sufficiently large, free diameter in the shape of a channel is to be provided, into which other parts can be inserted, as for example a motoric drive, a locking device or something of that sort.